A small broadband and low cost switched-beam smart antenna suitable for mobile WiMAX applications (band class 5–3.5 GHz) is presented in this paper. Present mobile terminal antennas are expected to show increased bandwidth as well as low-loss impedance matching while maintaining low-profile geometry. The proposed structure consists of four planar inverted-F antennas (PIFA) connected forming a cross, sharing the same ground plane, in a configuration designed for symmetrical coverage of the horizontal plane (Cross-PIFA). A custom genetic algorithm (GA) is used in order to optimize the proposed antenna parameters regarding resonant frequency and radiation pattern orientation angle and beamwidth. The optimized antenna exhibits small size (dimensions cm), satisfactory directivity for mobile terminal applications of 3.38 dB over an operation bandwidth of 120 MHz around the central frequency of 3.5 GHz. Simulation and measurement results and parameters range are exposed below followed by the according radiation pattern and variation of the VSWR indicating consistency between design and implementation.